cmake: Fix BUILD_SHARED_LIBS option and README for it

BUILD_SHARED_LIBS is a global flag so we don't need to set a default
option for it in both libhsakmt and hsa-runtime, only the top level
CMakeLists file. Also updated README to reflect that libhsakmt is
always built statically and gets linked to libhsa-runtime.

Change-Id: I1511f68a268032bec9758bc731d8074f33ec980f

CMakeLists.txt

@@ -48,6 +48,12 @@ project("rocr")
 
 set(CMAKE_VERBOSE_MAKEFILE ON)
 
+## Expose static library option
+if ( NOT DEFINED BUILD_SHARED_LIBS )
+  set ( BUILD_SHARED_LIBS ON )
+endif()
+set ( BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS} CACHE BOOL "Build shared library (.so) or not.")
+
 if (NOT DEFINED BUILD_ROCR)
   set(BUILD_ROCR ON)
 endif()

README.md

@@ -79,9 +79,9 @@ Ensure you have the following installed:
     ```
 
 - *Control whether libhsakmt and libhsa-runtime are shared or static*
-  The default (when `BUILD_SHARED_LIBS` is unset) is for libhsakmt to be static and libhsa-runtime to be shared. Setting `BUILD_SHARED_LIBS` to `OFF` will make both static and setting it to `ON` will make them both shared.
+    libhsakmt is always built as a static library that gets linked into libhsa-runtime, so there is a single library generated called libhsa-runtime64{.so/.a}. If `BUILD_SHARED_LIBS` is not set, this is a shared library by default. Setting `BUILD_SHARED_LIBS` to `OFF` will make it static.
     ```sh
-    -DBUILD_SHARED_LIBS=OFF   # or ON for both libs shared
+    -DBUILD_SHARED_LIBS=ON   # or OFF for static lib
     ```
 ### Building the tests
 #### rocrtst

libhsakmt/CMakeLists.txt

@@ -35,12 +35,6 @@ set(HSAKMT_STATIC_DRM_TARGET "${HSAKMT_TARGET}-staticdrm")
 
 project ( ${HSAKMT_TARGET} VERSION 1.9.0)
 
-# Build thunk as static by default
-if ( NOT DEFINED BUILD_SHARED_LIBS )
-  set ( BUILD_SHARED_LIBS "off" )
-endif()
-set ( BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS} CACHE BOOL "Build shared library (.so) or not.")
-
 # Optionally, build HSAKMT with ccache.
 set(ROCM_CCACHE_BUILD OFF CACHE BOOL "Set to ON for a ccache enabled build")
 if (ROCM_CCACHE_BUILD)

runtime/hsa-runtime/CMakeLists.txt

@@ -63,12 +63,6 @@ include ( utils )
 include ( hsa_common )
 include ( GNUInstallDirs )
 
-## Expose static library option
-if ( NOT DEFINED BUILD_SHARED_LIBS )
-  set ( BUILD_SHARED_LIBS ON )
-endif()
-set ( BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS} CACHE BOOL "Build shared library (.so) or not.")
-
 ## Adjust target name for static builds
 ## Original name will be an interface target that adds --whole-archive linker options around the target.
 if( NOT ${BUILD_SHARED_LIBS} )